The OmniTread OT-4 serpentine robot—design and performance

Serpentine robots are slender, multi-segmented vehicles designed to provide greater mobility than conventional mobile robots. Serpentine robots are ideally suited for urban search and rescue, military intelligence gathering, and inspection tasks in hazardous or inaccessible environments. One such serpentine robot, developed at the University of Michigan, is the “OmniTread OT-4.” The OT-4 comprises seven segments, which are linked to each other by six joints. The OT-4 can climb over obstacles that are much higher than the robot itself, propel itself inside pipes of different diameters, and traverse difficult terrain, such as rocks or the rubble of a collapsed structure. The foremost and unique design characteristic of the OT-4 is the use of pneumatic bellows to actuate the joints. The pneumatic bellows allow the simultaneous control of position and stiffness for each joint. Controllable stiffness is important in serpentine robots, which require stiff joints to cross gaps and compliant joints to conform to rough terrain for effective propulsion. Another unique feature of the OmniTread design is the coverage of all four sides of each segment with drive tracks. This design makes the robot indifferent to rollovers, which are bound to happen when the slender bodies of serpentine robots travel over rugged terrain. This paper describes the OmniTread concept and some of its technical features in some detail. In the Experiment Results Section, photographs of successful obstacle traverses illustrate the abilities of the OT-4. © 2007 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56171/1/20196_ftp.pd

A Tread/Limb/Serpentine Hybrid Robot: Toward Hypermobility in Deconstructed Environments

According to the Red Cross, an average of over 600 disasters and 100,000 associated deaths occur annually throughout the world. This frequency of disasters strains an already overburdened disaster response effort. In the first 48 hours of a rescue operation, it is estimated that a responder will get less than three hours of continuous sleep as they need to work at full force to set up the operation and begin work in the field. This leads to sleep deprivation during the most critical time for search and rescue of victims. Therefore, robots are greatly needed as a force multiplier in USAR response to reduce some of the burden and workload placed on the human rescue workers to make for a more efficient and effective response

Design and Analysis of Exaggerated Rectilinear Gait-Based Snake-Inspired Robots

Snake-inspired locomotion is much more maneuverable compared to conventional locomotion concepts and it enables a robot to navigate through rough terrain. A rectilinear gait is quite flexible and has the following benefits: functionality on a wide variety of terrains, enables a highly stable robot platform, and provides pure undulatory motion without passive wheels. These benefits make rectilinear gaits especially suitable for search and rescue applications. However, previous robot designs utilizing rectilinear gaits were slow in speed and required considerable vertical motion. This dissertation will explore the development and implementation of a new exaggerated rectilinear gait that which will enable high speed locomotion and more efficient operation in a snake-inspired robot platform. The exaggerated rectilinear gait will emulate the natural snake's rectilinear gait to gain the benefit a snake's terrain adaptability, but the sequence and range of joint motion will be greatly exaggerated to achieve higher velocities to support robot speeds within the range of human walking speed. The following issues will be investigated in this dissertation. First, this dissertation will address the challenge of developing a snake-inspired robot capable of executing exaggerated rectilinear gaits. To successfully execute the exaggerated rectilinear gait, a snake-inspired robot platform must be able to perform high speed linear expansion/contraction and pivoting motions between segments. In addition to high speed joint motion, the new mechanical architecture much also incorporate a method for providing positive traction during gait execution. Second, a new exaggerated gait dynamics model will be developed using well established kinematics and dynamics analysis techniques. In addition to the exaggerated rectilinear gaits which emphasize high speed, a set of exaggerated rectilinear gaits which emphasize high traction will also be developed for application on difficult terrain types. Finally, an exaggerated rectilinear that emphasizes energy efficiency is defined and analyzed. This dissertation provides the foundations for realizing a high speed limbless locomotion capable of meeting the needs of the search, rescue, and recovery applications

Design, Analysis, and Fabrication of a Snake-Inspired Robot with a Rectilinear Gait

Snake-inspired robots display promise in areas such as search, rescue and reconnaissance due to their ability to locomote through tight spaces. However, several specific issues regarding the design and analysis must be addressed in order to better design them. This thesis develops kinematic and dynamic models for a class of snake-inspired gait known as a rectilinear gait, where mechanism topology changes over the course of the gait. A model using an Eulerian framework and Coulomb friction yields torque expressions for the joints of the robot. B-spline curves are then used to generate a parametric optimization formulation for joint trajectory generation. Exact gradient computation of the torque functions is presented. A parametric model is used to describe the performance effects of changing system parameters such as mass, length, and motor speed. Finally, a snake-inspired robot is designed and fabricated in order to demonstrate both the vertical rectilinear gait and a modular, molded design aimed at reducing the cost of fabrication

Design, Analysis, and Fabrication of a Snake-Inspired Robot with a Rectilinear Gait

Snake-inspired robots display promise in areas such as search, rescue and reconnaissance due to their ability to locomote through tight spaces. However, several specific issues regarding the design and analysis must be addressed in order to better design them. This thesis develops kinematic and dynamic models for a class of snake-inspired gait known as a rectilinear gait, where mechanism topology changes over the course of the gait. A model using an Eulerian framework and Coulomb friction yields torque expressions for the joints of the robot. B-spline curves are then used to generate a parametric optimization formulation for joint trajectory generation. Exact gradient computation of the torque functions is presented. A parametric model is used to describe the performance effects of changing system parameters such as mass, length, and motor speed. Finally, a snake-inspired robot is designed and fabricated in order to demonstrate both the vertical rectilinear gait and a modular, molded design aimed at reducing the cost of fabrication

A Single Unit Concept And Design Of A High Maneuverability Mobile Robot

The aim of this project is to design and produce a mobile robot as a tool that could replace humans to perform certain tasks such as search, inspection, navigation and rescue in hazardous environments. The mobile robot has the ability to move in the environment such as air, soil and water. Some types of mobile robots that have been widely developed such as legged robots, wheeled robot with no arms, wall climbing robot and robot amphibians. The mobile robot is also known as bio-inspired robot. Snake robot is one example of a mobile robot. Snake robots are suitable for environment that is very limited because of the small cross section and highly redundant kinematics enables them to enter and move through narrow spaces. Robot snake promising mechanism for real-world applications such as search and rescue in destroyed city and industrial inspection. The degree of freedom gives them the potential to adapt to complex environments for confined spaces. Snake robots offer advantages over traditional mobile robots because they provide properties that can be achieved especially in an environment that convoluted. Thus, a mobile robot is generated using CAD software systems of SolidWorks and a prototype is produced to test it abilities. Physical appliances that have been used are an Arduino UNO, servo motors, and other electrical equipment. After that, the functional test and mechanism of the snake robot prototype has been carried out